In general, this invention relates to closure arrangements for containers of medicine and the like. More particularly, it relates to a cap adapted to cooperate with such a container to provide a precautionary arrangement and to be converted to provide an alternative easy open arrangement.
Various patents each disclose a combination involving a container and a cap that cooperate to define a precautionary arrangement directed to preventing children from removing the cap from the container. These patents give comprehensive explanations of the reasons why such a precautionary arrangement is needed; see, for example, U.S. Pat. No. 3,749,270.
A characteristic of such a precautionary arrangement is that a complex manipulation is required to remove the cap from the container. Typically such a complex manipulation involves, firstly, rotating the cap relative to the container until two position indicators, one on the cap and the other on the container, are brought into alignment, and then, secondly, lifting the cap off the container. Unless the cap is so angularly aligned with respect to the container, the cap is locked to the container. To achieve this locking, there is provided a radially projecting tab and a C-shaped flange that defines a notch through which the tab can pass. The tab can be on the cap and project radially inwardly for use with a complementary locking means involving such a C-shaped flange on the container. In an equivalent arrangement, the tab is on the container and projects radially outwardly therefrom, and the C-shaped flange is on the cap.
Athough such a precautionary arrangement is advantageous in circumstances where the need for safety exists, it constitutes a nuisance in other circumstances. For example, many elderly people never have small children in their homes. Moreover, owing to their age or to an affliction such as arthritis, such older people may be lacking in manual dexterity and accordingly find it difficult and sometimes impossible to remove the cap from the container so that they can take the medicine they need. Separately, the pharmacists who dispense the medicine fill many containers during a working day and are continually removing and replacing the caps. Owing to the complex manipulation described above, done repeatedly, the pharmacists suffer discomfort and irritation of their fingers and hands.
The foregoing problem arising from such precautionary arrangements has led to various proposals as to reversible closures. Examples of such a reversible closure are disclosed in U.S. Pat. Nos. 3,865,267, and 3,926,325. Each of these patents teaches a cap having a plug section at one end and having means defining a container-receiving recess at its opposite end.
There are drawbacks underlying the approach of providing such a plug/recess structure. It will be appreciated that cleanliness is especially important in this area. For this, and other reasons, the manufacturers who supply the containers and caps to dispensing pharmacists usually do so with the cap in place on the container. With a conventional precautionary arrangement, the container-receiving recess in the interior of the container cannot be contaminated during shipping and handling. However, with such a plug/recess structure, either the plug or the container-receiving recess is exposed during shipping and handling and thereby is likely to become contaminated unless additional provision is made for cleanliness.